Multi-carrier synchronizing system and synchronizing method

Abstract

The invention discloses a multi-carrier synchronizing system and a multi-carrier synchronizing method which are applied to an OFDM multi-carrier system. The multi-carrier synchronizing system comprises a symbol synchronizing module and a frame synchronizing module, wherein the symbol synchronizing module carries out related calculation on a received sequence and a local sequence and determines the symbol synchronizing position by detecting the related peak value of a continuous symbol window, the frame synchronizing module calculates the cumulative sum of the differentials between a phase of a current symbol and an average phase of former symbols, compares the cumulative sum with a preset judgment threshold and finds out the frame synchronizing position after judgment. The multi-carrier synchronizing method comprises the steps of carrying out related calculation on received signals and the local sequence after average filtering is carried out on the received signals, determining the symbol synchronizing position by detecting the related peak value of the continuous window, and judging whether frames are synchronized by calculating the phase differential of two continuous symbols according to the symbol synchronizing position. Compared with the existing synchronizing technology, the multi-carrier synchronizing system and the multi-carrier synchronizing method have the advantages of being low in complexity, high in accuracy and capable of being achieved easily through hardware.

Description

technical field [0001] The present invention relates to the field of digital communication, in particular to a synchronization system and method for an OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) multi-carrier system. Background technique [0002] OFDM is a multi-carrier communication technology with high-speed data transmission capability. It has the advantages of high spectrum utilization, anti-interference, and anti-fading capabilities. It has become the core technology in the field of communication and is widely used in various communication systems, such as Wireless local area network, digital audio / video broadcasting, etc., have broad application prospects. [0003] Synchronization technology is a practical problem that any communication system needs to solve, and its performance is directly related to the quality of the entire communication system. The OFDM multi-carrier system is very sensitive to synchronization err...

AI Technical Summary

Problems solved by technology

[0004] There are currently two popular symbol synchronization methods. One is the delay correlation detection method. This method needs to normalize the correlation value, requires a large number of multiplication and division operations, and has a large hardware resource overhead. In addition, the correlation result is affected by the signal-to-noise ratio. The impact is greater, the correlation output is a platform, the boundary points are blurred, and it is not easy to detect, which may lead to inaccurate or unsynchronized symbol synchronization; the second is the autocorrelation peak detection method, which has a sharp correlation peak and is easy to detect, and the energy of the local sequence is It is known that a part of the calculation amount is reduced, but the correlation value also needs to be normalized, and there is also the problem of being easily affected by noise. When the signal-to-noise ratio is low, the main peak may not reach the threshold or the value of the interference peak exceeds threshold phenomenon

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